Simultaneous recording or reproduction of sounds and moving pictures



Nov. 1, 1932. J. R. ROBERTSON I 1,885,293

SIMULTANEOUS RECORDING OR REPRODUCTION OF SOUNDS AND MOVING PICTURES Filed Jan. 23, 1950 1 iiiii u 1 ,v" H

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Patented Nov. 1, 1932 UNITED STATES PATENT OFFICE.

JAMES ROBERT ROBERTSON,'OF. LONDON, ENGLAND Application filed January 23, 1930, Serial No. 422,891, and in Great Britain January 23,1929.

The present invention relates to the simultaneous recording or reproduction of sounds and moving pictures and provides improved means for ensuring synchronism between the sounds and the picture to which they relate. The invention is however, not limited to arrangements in which exact synchronism is required and is also applicable where the sounds are in the nature of an accompaniment to the pictures.

It has already been proposed to drive a sound record or blank by means of a picture film, the film which is driven past a picture reproducing or recording gate being drawn from a reel geared to the sound record or blank carrier. In this way although the film is moved at constant velocity through the picture gate, the speed of the reel, and consequently of the sound record, is increased as the film unwinds from the reel. The record speed is not therefore proportional to the film speed.

According to the present invention, there is provided apparatus for reproducing re corded sound from a disc or cylindrical sound record or for recording sound upon a disc or cylindrical blank wherein the carrier for said record or blank is adapted to be driven mechanically by a moving picture film at a speed proportional to the linear speed of said film.

The invention is illustrated in one form in the accompanying drawing in which Fig. 1 shows diagrammatically a combined sound and picture reproducing system in accordance with the present invention, whilst Fig. 2 shows a detail of the system of Fig. 1.

Referring to the drawing, the picture film 1 after passing through the projector 2 is passed around sprockets 3 and 4 which are rigidly secured to the shaft of the turntables 5 and 6 respectively. The film 1 then passes around the sprocket 7 which is mechanically coupled by any kn own or suitable means with the projector driving mechanism. As shown, such means comprises a shaft 18 having at one end a bevel gear 17 meshing with a bevel pinion, 16, on the shaft of the sprocket 7 and having at its other end a worm 19 which engages a gear'15of the proyector driving.

mechanism. The sprocket arrangement is more clearly shown in Fig; 2; The sprocket teeth engage with the usual perforations which. are provided in'thesides of the film 1. Clearly, the speed of the turntables-5 and 6' will be proportional tothe linear speed of the filin- 1.

The turntables 5 and 6 may be provided as shown with downwardly projecting ,metal flanges 8 and 9' respectively which, when the turntables rotate, pass between the poles of the magnets 10 anddl. Thus eddy current damping-pf the turntables takes place and prevents them over runningthe driving film- 1. Alt'ern atively, friction brakes, which ma y be magnetically; pneumatically, or mechanicallyoperated, may be'used to preventoverrunning:

If desired, a second sprocket mechanically coupled tothesprocket 7 may be provided in engagementwiththe film between the sprockets 3nd 4'.

Although the-sprockets 3 and 4 are'shown mounted upon the turntable spindles it will beclear that they may, if desired, be coupled thereto by gearing.

A similar arrangement'may' beadopted when recording, a wax blank in this case replacing the disc record.

The change in reproduction from one record to reproduction from another may be carried out automatically by suitable means actuated by the picture film. For example, special perforations may be provided in the film and those perforations may engage switch mechanism which either changes the electrical connections between two electrical pick-up devices 12 and 13, co-operating with their respective records and the remainder of the sound reproducing apparatus, throwing one out of circuit and inserting the other at the appropriate moment, or the switch mechanism may actuate solenoids or the like which lift one pick-up device from engagement with its record and allow the other to drop into engagement with the other record. Instead of the perforations in the film suitable markings may be provided upon the film and these markings may be arranged to modify the light falling upon a light sensitive device and produce electrical variations therein which can be used to actuate the change over mechanism, the solenoids and the magnetic brakes.

In Fig. 1 of the drawing there is shown a photographic sound reproducing device 1 L through which the film 1 is passed between the projector 2 and the sprocket 3. This may be used either as a stand-by in case of breakdown of the other sound reproducing mechanism or it may be used to reproduce sounds simultaneously with those produced from the other sound records.

I claim:

1. In a combined sound and picture recording or reproducing means, the combination with a motion picture apparatus and means for propelling a film therethrough, of a rotatable table-like support for a sound record or blank, a film sprocket mechanically coupled to said table, a second film sprocket mechanically coupled to the film propelling means and adapted to drive the first named sprocket with the aid of a tensioned film, and a braking means cooperating with the rotatable table-like support and adapted to'prevent overrunning thereof.

30 2. In a combined sound and picture reproducing apparatus, the combination of a motion picture projector, means for propelling a film through said projector, rotatable means adapted to support a sound record, a film 5 sprocket connected to said support to rotate therewith, a second film sprocket mechanically coupled to the film propelling means and adapted to drive the first named sprocket with the aid of a tensioned film, and braking 40 means cooperating with said rotatable means and adapted to prevent overrunning thereof,

In testimony whereof I have signed my name to this specification.

JAMES ROBERT ROBERTSON. 

